1. Field of the Invention
This invention relates to a line head device to be incorporated in a paper processing apparatus such as electrophotographic printing apparatus or facsimiles.
2. Description of the Related Art
In ordinary electrophotographic printing apparatus, a surface of the photosensitive drum is uniformly electrified and selectively exposed, according to the input image information, to form an electrostatic latent image. The latent image is developed by toner fed to the photosensitive drum. The toner adheres to the surface of the photosensitive drum in accordance with the latent image, making the latent image visible as a toner image. The toner image is transferred from the surface of the photosensitive drum to a sheet of charged paper by electrostatic attraction. After the image transfer, the toner image is fixed to the paper by using heat and temperature. For exposure of the photosensitive drum, the following line head is used, for example. This line head is composed of an array of edge light-emitting elements arranged in one row, and is secured so as to be parallel with the axis of the photosensitive drum. A paper feeding mechanism picks up sheets of paper stored in a paper cassette one by one, and delivers the paper sheet to the transfer or print position.
Before shipment of those devices, manufacturers check to see if they operate properly. Actual inspection sometimes finds that a printed image is deviated from a desired position due to the misalignment of paper. In this case, the line head position will be adjusted or the operation of the feeding mechanism will be corrected. This work is troublesome and require high accuracy.